What system in the body is responsible for transporting oxygen, waste, nutrients, hormones, and heat?

The circulatory system is primarily responsible for transporting essential substances throughout the body, including oxygen, waste products, nutrients, hormones, and heat. The heart, blood vessels, and blood work together in this system.

Oxygen is transported from the lungs to the cells, while carbon dioxide, a waste product of cellular respiration, is carried back to the lungs for exhalation. Nutrients from digested food are absorbed into the bloodstream and delivered to cells to provide energy. Hormones, which are produced by various glands, are distributed through the circulatory system to target organs to regulate functions and maintain homeostasis. Additionally, the circulatory system helps in regulating body temperature by distributing heat generated by metabolism and by adjusting blood flow to the skin.

Thus, the circulatory system plays a critical role in maintaining the body's overall functionality and health.